Last time I was in Dubai, my return plane to UK was cancelled. Bad luck, but the company was not willing to offer any help better than "come back in 2 days" [1]. There are protective rules for passengers who suffer such uncomfortable situation. Unfortunately it depends whether you are flying in Europe, US or the rest of the world.

In Europe, the European Union Air Passenger Rights rules for delayed and cancel flights apply to all passengers with a confirmed reservation for any flight taking off from any EU airport or flying to a European airport on a EU member's plane company.

Passengers who are delayed for more than 5 hours may request a refund of their ticket and free accommodation, but only if they decide not to travel. In case of cancellation, you are entitled to compensation of € 125 for short flights to € 600 for long flights, and have the choice of rerouting or refund, plus meals, refreshments, 2 phone calls.

Financial compensation is due unless you were informed 14 days before the flight, or you were
rerouted close to your original times, or the airline an prove that the cancellation was caused by extraordinary circumstances (unfortunately this is unclear and has been used by many airplanes to deny compensation, using the wording "extraordinary circumstances" for strikes, fog, snow in Scandinavia...etc).

• If your flight depart from a EU country, call the freephone number during working hours (09:00–18:30 CET weekdays): 00 800 6 7 8 9 10 11
• From outside the EU call (normal charges apply): (32-2) 299 96 96
• or by email: mail@europe-direct.cec.eu.int

In the United States, airlines are not required to compensate passengers. You can find information on http://airconsumer.ost.dot.gov/problems.htm

[1] Don't worry, a bit of stuborness and experience and I managed to catch a plane within the hour